The development of a controlled release system to deliver antibiotic drugs to the periodontal pocket is proposed. This system could result in improved treatment of periodontal disease. The system consists of antibiotic containing microparticles, 100 Mum in diameter, formulated as a suspension in a carrier media. One formulation, to be used in the dental office, would be formulated in a paste. This paste would be placed in the periodontal pocket by the dentist, using a syringe and thin rubber tube. The microparticles in the paste would release the antibiotic for a two to four week period, after which residual paste would be removed or replaced with fresh material. The second formulation would be applied by periodontal patients. The microparticles in this formulation would release the antibiotic for one to three days. These microparticles would be formulated in a cream suspension and would be rubbed over the gums by the patient daily. A fraction of the particles applied would lodge in the periodontal pocket or teeth crevices, while the remainder would be removed by a mouth rinse. Both formulations would control antibiotic release by slow diffusion through a suitable microparticle matrix polymer.